In the file, classes/admin/WCST_ActivationPage.php find the function render_product_fields_meta_box which starts around line 127, straight after this line of code:
$domain = $_SERVER['SERVER_NAME'];
Now in the WP dashboard when you see the message “To complete the WooCommerce Shipping Tracking plugin activation, you must verify your purchase license. Click here to verify it.”, click on the link and you will see the plugin has been activated.
Now refresh the dashboard and you’re good to go.